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EP-4619648-B1 - WEDGE LOCK WASHER PAIR AND TENSIONING ARRANGEMENT WITH SUCH WEDGE LOCK WASHER PAIR

EP4619648B1EP 4619648 B1EP4619648 B1EP 4619648B1EP-4619648-B1

Inventors

  • LUTTER, FRANK
  • VORNWEG, Stefan

Dates

Publication Date
20260513
Application Date
20250129

Claims (16)

  1. A pair of wedge lock washers comprising: a first wedge lock washer (2, 2.1) and with a second wedge lock washer (3, 3.1), with the first wedge lock washer (2, 2.1) having a larger outer diameter than the second wedge lock washer (3, 3.1), wherein the two wedge lock washers (2, 3; 2.1, 3.1) each have a fastener opening (6, 6.1) arranged in alignment with one another, and on inner disk surfaces thereof facing one another, a wedge surface structure which engage one another, and clamping structures (9, 9.1; 9.2, 9.3) on outer disk surfaces thereof facing away from one another, wherein the first wedge lock washer (2, 2.1) has a rotary drive contour (7) on a radial outer side thereof for torque support of a clamping tool, wherein the clamping structures (9, 9.2) of the first wedge lock washer (2, 2.1) are configured for a form-fitting embossing thereof into a surface of a component (16) arranged adjacent thereto, wherein apexes (5, 5.1) of the wedge surface structures are arranged as positive structures on the mutually facing disk surfaces of the two wedge lock washers (2, 3; 2.1, 3.1) in each case in a respective plane, characterized, in that the clamping structures (9, 9.2) of the first wedge lock washer (2, 2.1) are arranged at least in a radially outer disk section (10) extending in the radial direction at an axial distance from the outer disk surface in an inner disk section (12), and the planes of the inner and outer disk surfaces of the second wedge lock washer (3, 3.1) are arranged parallel to one another.
  2. The pair of wedge lock washers of claim 1, wherein the outer diameter of the second wedge lock (3, 3.1) washer extends to an inner diameter of the radially outer disk section (10) of the first wedge lock washer (2, 2.1).
  3. The pair of wedge lock washers of claim 1 or 2, wherein a material thickness of the first wedge lock washer (2, 2.1) decreases from the radially outer disk section (10) arranged at an axial distance from the inner disk section (12) in a direction of the fastener opening (6).
  4. The pair of wedge lock washers a to anyone of a to claims 1 to 3, wherein the radially outer disk section (10) arranged at an axial distance from the inner disk section (12) extends approximately 25 to 45% of the radial washer extension starting from the edge of the fastener opening (6).
  5. The pair of wedge lock washers a to anyone of a to anyone claims 1 to 3, wherein the clamping structures (9, 9.1; 9.2, 9.3) are formed as radial ribs.
  6. The pair of wedge lock washers of claim 5, wherein the radial ribs extend from an edge region enclosing the fastener opening (6, 6.1) into a region of the radially outer end of the respective wedge lock washer (2, 3; 2.1, 3.1).
  7. The pair of wedge lock washers of claim 5 or 6, wherein the radial ribs have an asymmetrical cross-sectional geometry with flatter flanks thereof aligned in opposite directions to the wedge surfaces (4, 4.1) structuring the opposite disk surface.
  8. The pair of wedge lock washers to anyone of claims 5 to 7, wherein a first number of radial ribs (R1) have a first height and a second number of radial ribs (R2, R3) have another height which is less than the first height, and the radial ribs of the first number are separated from one another individually or in groups by at least one radial rib (R2, R3) of the second number.
  9. The pair of wedge lock washer of claim 8, wherein the second number of radial ribs (R2, R3) is composed of radial ribs with at least two different heights.
  10. The pair of wedge lock washer of claim 9, wherein, viewed in the circumferential direction of the lock washer (2, 3.1), starting from a radial rib (R1) of the first number, the radial rib (R1) of the first number is followed by two or more radial ribs (R2, R3) of the second number of sequentially decreasing height.
  11. The pair of wedge lock washer of claim 10, wherein a sequence of radial ribs (R1, R2, R3) of varying height is the same in both circumferential directions of the lock washer (2, 3.1).
  12. The pair of wedge lock washers to anyone of claims 1 to 11, wherein the two wedge lock washers (2, 3; 2.1, 3.1) are each produced by a stamping-pressing process from steel or stainless steel.
  13. The pair of wedge lock washers to anyone of claims 1 to 12, wherein the two wedge lock washers (2, 3; 2.1, 3.1) are provided, at least on the disk surfaces thereof, with a zinc flake coating.
  14. The pair of wedge lock washers to anyone of claims 1 to 13, wherein the two wedge lock washers (2, 3; 2.1, 3.1) with their engaged wedge surfaces (4, 4.1) are held together in a delivery state by an adhesive connection which is flexible or detachable with respect to a shear stress.
  15. A clamping arrangement for clamping at least two components (16, 17) together using a screw fastener, comprising a pair of wedge lock washers (1, 1.1) according to anyone of claims 1 to 14, wherein in the clamping arrangement (15), the first wedge lock washer (2, 2.1) rests on a surface of one of the components (16), and the screw fastener with a clamping nut or a head (22) of a clamping bolt (20) rests on the second wedge lock washer (3, 3.1), and wherein at least the clamping structures located in the radially outer disk section (10) of the first wedge lock washer (2, 2.1) are embossed by a clamping process into the surface of the component (16) resting thereon in a form-fitting manner with respect to the circumferential direction of the first wedge lock washer (2, 2.1).
  16. A clamping arrangement for clamping at least two components (16) together using a screw fastener, comprising a pair of wedge lock washers (1, 1.1) according to anyone of claims 1 to 11, wherein in the clamping arrangement (26), the second wedge lock washer (3, 3.1) rests on a surface of one of the components (16), and the screw fastener with a clamping nut or a head (22) of a clamping bolt (20) rests on the first wedge lock washer (2, 2.1), and wherein through such arrangement of the pair of wedge lock washers (1, 1.1), a force required for loosening is greater than a force required for tightening the clamping arrangement.

Description

The invention relates to a pair of wedge lock washers with a first wedge lock washer and with a second wedge lock washer according to the preamble of claim 1. Wedge lock washers are used as anti-loosening devices, particularly for securing complex screw connections. While the clamping structures designed as radial ribs on the surfaces of the two wedge lock washers facing away from each other serve the purpose of increasing friction on the respective counter support surface, for example the underside of a screw head or the surface of an object in the loosening direction, the wedge surfaces of the wedge surface structuring facing each other on the opposite surfaces of the wedge lock washers serve to prevent self-loosening. This is possible because the pitch of the wedge surfaces is designed to be the same as the pitch of the thread of a screw as a screw fastener, but with a larger pitch angle. Due to the increased frictional resistance in the release direction between the pair of wedge lock washers and the respective counter support, only one movement is possible between the two disks, which, however, is blocked due to the orientation and inclination of the wedge surfaces with respect to self-release movements. Such pairs of wedge lock washers are particularly suitable for securing dynamically stressed screw connections, since the height of the interlocking wedge surfaces of the two washers means that the desired locking function is maintained for much longer than when using other locking systems. The same applies to screw connections that are subject to thermal length changes. The above-described functioning of such a pair of wedge lock washers is particularly safe when the clamping structures on the side facing the surface of the component are pressed into the surface material of this component in a form-fitting manner in the circumferential direction of the washer. It is important that this form-fitting connection is maintained even under mechanical and/or thermal loads to which the pair of wedge lock washers is exposed when part of a clamping arrangement. In order to improve the stability of the above-described form fit between the pair of wedge lock washers and the component that is in contact with and thus clamped, over the period of use, a pair of wedge lock washers has been proposed in DE 20 2012 103 313 U1, in which at least one of the two wedge lock washers of equal diameter, typically at least the one that is in contact with the surface of the component with its clamping structures, is designed in the manner of a disk spring. In order to implement the principle described in this prior art, it is necessary that one or both of the wedge lock washers, designed in the manner of a disk spring, are made of spring steel. Due to the nature of the material, machining spring steel to create the required structures on the flat sides is much more complex than producing a conventional pair of wedge lock washers, where the wedge lock washers are not made of spring steel. US 2019/0178284 A1 discloses a pair of wedge lock washers with one of the two wedge lock washers having a larger diameter than the other. The wedge lock washer, which has a larger diameter, has a radial external toothing, which provides a rotary drive contour for the torque-locking engagement of a torque support of a clamping tool. This pair of wedge lock washers is designed like a reaction washer. In principle, this wedge lock washer is also designed like a disk spring. Both flat sides are conically tapered towards the fastener opening. This means that the wedge surface structures as well as the clamping structures are located on conical disk surfaces. With regard to the upper surface of the disk carrying the clamping structures, this serves the purpose of ensuring that, before clamping, only the radially outer disk section with its clamping structures located thereon rests on the surface of the component to be clamped. The arrangement of the clamping structures of the smaller diameter wedge lock washer on its counter bearing is reversed. In the case of the smaller diameter wedge lock washer, only the inner disk section with the clamping structures located on it rests on the surface of a counter bearing, for example a clamping nut or the underside of the head of a clamping bolt. This means that during the clamping of the clamping arrangement in which this pair of wedge lock washers is inserted, first the clamping structures of the outer disk section of the wedge lock washer with the larger diameter are pressed into the surface of the component and then this wedge lock washer is adjusted like a disk spring so that, in the clamping position, this wedge lock washer rests with its entire intended disk surface on the surface of the component. The wedge lock washer with a smaller diameter does not have any clamping structures on its surface facing away from the wedge lock washer with a larger diameter, which are intended to create a positive connecti